Answer: stiffest

AnswerCrossword Clue
STIFFESTMost severe, as a penalty
STIFFESTMost difficult.
stiffestSevere or strong
stiffest(of a wind) Blowing strongly
stiffestA card that is the only one of its suit in a hand
stiffestViscous; thick
stiffestNot moving as freely as is usual or desirable; difficult to turn or operate
stiffestHaving a specified unpleasant feeling to an extreme extent
stiffestRequiring strength or effort; difficult
stiffestNot easily bent or changed in shape; rigid
stiffestFull of
stiffest(of a person or their manner) Not relaxed or friendly; constrained
stiffest(of an alcoholic drink) Strong
stiffest(of a person or part of the body) Unable to move easily and without pain
stiffestSTIFF, not easily bent